GAIN CORRECTING APPARATUS FOR THERMAL TYPE FLOW VELOCITY SENSOR FOR GAS METER

摘要

PURPOSE:To surely correct the gain of a thermal type flow velocity sensor at the time of practical use and correct the error attributed to the difference of the density of air and a gas. CONSTITUTION:A gain correcting circuit 41 corrects the gain of a flow velocity sensor 30 corresponding to the difference of the density of air and a gas when the fluid which passes the inside of a gas meter is changed from air to gas. A flow rate computing part 5 takes the data, which is obtained by analog/digital conversion of the output of the gain correcting circuit 41 by an A/D converter 42, and computes the flow rate.